Abstract: CFD method was used to investigate the thermal hydraulic characteristics of the printed circuit heat exchangers (PCHE) with zigzag channels, and the physical parameters of supercritical CO2 was calculated by combining the physical property fitting formulas and the user defined function (UDF ). In addition, the turbulent flow model was based on the SST k-ω model, and the CFD method was validated by the experimental data of friction coefficient and heat transfer coefficient. Simulation results show that in the zigzag channels of PCHE, the core accelerating area moves toward the outside wall at the bending point, and the separated flow area becomes narrow as the pressure drop decreases at the downstream part of the bending point.